1. Field of the Invention
The present invention relates to a porous film microfluidic device, and particularly to a porous film microfluidic device for automatic surface plasmon resonance quantitative analysis.
2. Description of Related Art
In the field of chip detection technology, detection is generally realized by changes in optical signals, in particular fluorescence signals. Although most changes in fluorescence signals are conveniently observable to the naked eye, it however, lacks sufficient sensitivity. Recently, in order to enhance the detection sensitivity, a change in the intensity of the reflected light due to the surface plasmon resonance (SPR) phenomenon has been served as the basis of the detection. As for the detection of a biological sample, biomolecules are attached to a gold (Au) or silver (Ag) film and the binding between the sample and the metal film is determined by detecting the change in the intensity of reflected light before and after the binding, which provides a high detecting discrimination.
Currently, some technologies use SPR as a platform to incorporate microfluidic chips to detect the biological or chemical samples. According to the currently known microfluidic chip technology, an external force, typically exerted by a pump is used to inject the sample into the microfluidic channel to combine with the biomolecules. The necessity for using a pump brings much inconvenience to chip detection. Specifically, the known microfluidic chip may not be applicable to detect a trace amount of sample from an animal or a plant because the sample volume is too little to be injected into the microfluidic channel. Besides, a high evaporation rate of these samples may be another technical barrier for detection, and thus, the application of the known microfluidic chip will be limited.
In order to effectively achieve cost reduction and the convenience of use outside the laboratory, a microfluidic platform with lateral flow test strips has been proposed. However, the sample in the conventional microfluidic platform with lateral flow test strips easily evaporates, and a multi-step processes cannot be conducted. As a result, the improvement on the detection sensitivity of detection of a trace amount of sample is not possible, and the detection accuracy can be reduced easily.
In view of the above drawbacks, what is needed is to develop a microfluidic chip, by which a trace amount of sample can be injected without using a pump and with a reduced evaporation rate, to thereby increase its maneuverability and expand its applications.